Sayyiduna Jabir (may Allah be pleased with him) narrates: When revelation came down upon the Prophet (peace and blessings be upon him), or when he was admonishing, I would think that he was warning a people upon whom punishment was about to come. And when that state of his had passed, I would think that he was the most cheerful-faced, the most smiling and the best-mannered of people.
Imam al-Bazzar recorded this narration, and its chain is hasan (good).